Show count of not_cloned/cloned/cloning/failed in admin UI

Created by: mrnugget

This adds repository counts to the site-admin repositories page.

Under the hood, the SQL query used to count the repositories is not as efficient as it can be, because the first attempt in https://github.com/sourcegraph/sourcegraph/pull/39660 was a deadend. But I have an idea for a better solution.

Until I have that efficient solution done, though, I don't think it's harmful to ship this version, which does a single SELECT when viewing the page.

This also uses the new UI components that @erzhtor and @thenamankumar added for the analytics pages (cc @rob) to display the counts.

Demo video

https://user-images.githubusercontent.com/1185253/185087781-4b223777-49ed-4b1b-aa51-cff459ac8d6f.mp4

Test plan

• Unit tests
• Manual testing